Electric timepiece



17, 1965 R. BESSON 3,200,578

ELEQTRIC TIMEPIECE Filed April 28, 1964 I INVENTOR. RENE BESSON ATTO RN EY United States Patent 3,26%),573 ELECTRIC TIMEPIECE Ren Besson, Les Loges, Switzerland, assignor to Ebauches S.A., Nenehatel, Switzeriand, a Swiss firm Filed Apr. 28, 1%4, Ser. No. 363,132 Claims priority, application Switzerland, May 7, 1963, 5,732/63 2 Claims. (Cl. 58-23) The present invention relates to an electric timepiece having an electronic circuit comprising at least one transistor, the base of which is polarised by the source of current for the timepiece.

In electric timepieces of the above-mentioned type, it is necessary, for the purpose of storing the timepiece and so as to avoid the excessive use of rest current during storage, due to the polarisation of the base of the transistor, to make provision for the disconnecting of the source of current, generally by means of a switch placed on one of the terminals of the source. The disadvantage in this arrangement resides in the fact that, if a fault occurs in the operation of the switch, the timepiece is positively stopped.

It is an object of the present invention to provid means which will preclude the flow of an excessive rest current, when the timepiece is stopped during storage, without it being possible for a fault to occur which would be resultant in the final stopping of the timepiece.

The timepiece, according to the invention, is characterise-d by the fact that it comprises a switch connected between the base and the emitter of the transistor so that, when the switch is closed, the base and the emitter of the transistor are short-circuited, whereby, with the regulating member of the timepiece stopped, the rest current delivered by the current source is substantially lower than the current which would be consumed if the said switch were not so provided.

The invention will now be described more fully with reference to the accompanying drawing which shows, by Way of example only, one form of electric timepiece constructed in accordance with the invention. In the drawmg:

FIGURE 1 is a plan view of the movement of the timepiece, and

FIGURE 2 is an electronic circuit diagram of the timepiece.

Referring to the drawing, the timepiece illustrated comprises an electric cell which is not visible in FIGURE 1, but is represented diagrammatically at 1 in FIGURE 2. Through the medium of two coils, namely a pick-up coil 2 and a driving coil 3, cell 1 maintains the balance member, designated by the reference 4, in oscillation. The electronic circuit, which is carried entirely by an insulating plate 5 in the form of an annular segment, comprises printed conductors, a transistor 6, a resistance 7 and two condensers 8 and 9.

This electronic circuit also includes a switch 10 connected between the base and the emitter of the transistor 6 and controlled by a pivotable lever 11 which is biased by a wire spring 16 and has a projection 11a engaging in a groove 12 in a hand-setting pinion 13 provided with contrate teeth 13a.

When the hands are set, a pull is exerted on the stem, designated by the reference 14, which carries the pinion 13, so as to cause the pivotable lever 11 to turn in a clockwise direction about its pivot, which is designated 3,209,578 Patented Aug. 17, 1965 by the reference 15. The pivotable lever therefore closes the contact 10, short-circuiting the base and the emitter of the transistor 6. At the same time, the end 16a of the ire spring 16 acts on the balance member 4 so as to stop it. It should be noted that the balance member has a notch 17 with which the wire spring 16 cooperates, in the manner of a pawl, so as to keep the balance member stopped beyond its position of equilibrium.

When the watch is stored, the stem 14 is brought into the hand-setting position so as to stop the movement. In this rest or inoperative position, the current supplied by the cell is very low, i.e. between 0.5 and I ia. or about 20 to times less than the current consumed when the switch 10 is open. This is due to the fact that the polarisation current of the transistor is greater than the threshold of conduction, this current being greater than the average current consumption during the working of the watch. Thus, the energy used after storage for one year, for

example, will be less than 10 m. A.h.

It should be observed that the contact 10 may be very poor electrically, it being possible for the resistance of this contact to amount to as much as 0.5 M52 without the rest current being affected thereby. The advantage of this arrangement resides in the fact that, if the contact 10 should happen to be a-ccidentially opened once and for all, the timepiece would nevertheless continue to function correctly.

The present arrangement could also apply to the case where the electronic circuit does not serve to control the regulating member of the timepiece directly, but rather serves, for example, .to wind a mainspring intermittently. In such a case, it would be advantageous to close the switch 10 between each winding operation in order to avoid unnecessary loss of current. Provision could be made for the successive closing and opening actions of the switch It) to be produced automatically by the timepiece itself.

What I claim is:

1. In the electronic circuit of an electric timepiece including a regulating member, the combination of: a source of current, a transistor inclusive of an emitter and a base polarized by said source of current, and a switch connected between the base and emitter of said transistor for the short circuiting of the base and emitter in the switchclosed position under rest current conditions of less-thannormal current consumption while the regulating member is stopped.

2. In the electronic circuit cooperant with the balance member of an electric timepiece, the combination of: a source of current, pick up and driving coils connected to said source of current for maintaining the balance member in oscillation, a transistor having an emitter and base, a resistance, a pair of condensers, a normally-open switch connected between the base and emitter of said transistor,

and control means for rendering the switch into and out of switch-closed position for the short-circuiting of the base and emitter of said transistor under a low current consumption condition and the stoppage of the oscillation of the balance member during a period of timepiece non-use.

No references cited.

LEYLAND M. MARTIN, Primary Examiner. LEO SMILOW, Examiner. 

1. IN THE ELECTRONIC CIRCUIT OF AN ELECTRIC TIMEPIECE INCLUDING A REGULATING MEMBER, THE COMBINATION OF: A SOURCE OF CURRENT, A TRANSISTOR INCLUSIVE OF AN EMITTER AND A BASE POLARIZED BY SAID SOURCE OF CURRENT, AND A SWITCH CONNECTED BETWEEN THE BASE AND EMITTER OF SAID TRANSISTOR FOR THE SHORT CIRCUITING OF THE BASE AND EMITTER IN THE SWITCHCLOSED POSITION UNDER REST CURRENT CONDITIONS OF LESS-THANNORMAL CURRENT CONSUMPTION WHILE THE REGULATING MEMBER IS STOPPED. 